帮忙看一下这段代码为什么没有效果。谢谢

//我想给所有有required式样的textbox加onkeypress事件，在onkeypress的时候改变背景色。
//但是我些的下面这段代码没有起作用。
//麻烦高手解释一下。谢谢
$(document).ready(function(){            
                $('.required').each(function (index, domEle){                
                    $(domEle).onkeypress = function ()
                    {              
                        $(this).css('background-color','blue');
                    }          
                }
            );
        });
    
  
//处理单个textbox的时候有效果，不知道为什么上面的一段不行。
         $(document).ready(function(){
                    $('.required')[0].onkeypress = function()
                    {
                        $(this).css('background-color','blue');
                    }
          });

            $('.required').each(function (index, domEle){                
                    $(this).onkeypress = function ()
                    {              
                        $(this).css('background-color','blue');
                    }          
                }

再顶一下，麻烦高手出来解决一下啊。

//自己解决了，贴出答案。


$(document).ready(
            function(){            
                $('.required').each(function (index, domEle){                
                    $(domEle).bind('keypress' , function ()
                                                {              
                                                 $(this).css('background-color','white');
                                                }                          
                                  );//End of bind
                                    }//End of  each function
                               )//End of each
            }//End of ready function
        );//End of ready